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Braglia C, Alberoni D, Di Gioia D, Giacomelli A, Bocquet M, Bulet P. Application of a robust MALDI mass spectrometry approach for bee pollen investigation. Anal Bioanal Chem 2024; 416:4315-4324. [PMID: 38879687 PMCID: PMC11271380 DOI: 10.1007/s00216-024-05368-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2024] [Revised: 05/22/2024] [Accepted: 05/27/2024] [Indexed: 07/23/2024]
Abstract
Pollen collected by pollinators can be used as a marker of the foraging behavior as well as indicate the botanical species present in each environment. Pollen intake is essential for pollinators' health and survival. During the foraging activity, some pollinators, such as honeybees, manipulate the collected pollen mixing it with salivary secretions and nectar (corbicular pollen) changing the pollen chemical profile. Different tools have been developed for the identification of the botanical origin of pollen, based on microscopy, spectrometry, or molecular markers. However, up to date, corbicular pollen has never been investigated. In our work, corbicular pollen from 5 regions with different climate conditions was collected during spring. Pollens were identified with microscopy-based techniques, and then analyzed in MALDI-MS. Four different chemical extraction solutions and two physical disruption methods were tested to achieve a MALDI-MS effective protocol. The best performance was obtained using a sonication disruption method after extraction with acetic acid or trifluoroacetic acid. Therefore, we propose a new rapid and reliable methodology for the identification of the botanical origin of the corbicular pollens using MALDI-MS. This new approach opens to a wide range of environmental studies spanning from plant biodiversity to ecosystem trophic interactions.
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Affiliation(s)
- Chiara Braglia
- Dipartimento di Scienze e Tecnologie Agro-Alimentari (DISTAL), Università di Bologna, Viale Fanin 42, 40127, Bologna, Italia
| | - Daniele Alberoni
- Dipartimento di Scienze e Tecnologie Agro-Alimentari (DISTAL), Università di Bologna, Viale Fanin 42, 40127, Bologna, Italia.
| | - Diana Di Gioia
- Dipartimento di Scienze e Tecnologie Agro-Alimentari (DISTAL), Università di Bologna, Viale Fanin 42, 40127, Bologna, Italia
| | - Alessandra Giacomelli
- Unione Nazionale Associazioni Apicoltori Italiani (UNA API), Via Pietro Boselli 2, Firenze, Italia
| | - Michel Bocquet
- Apimedia, 82 Route de Proméry, Pringy, 74370, Annecy, France
| | - Philippe Bulet
- CR, University Grenoble Alpes, IAB Inserm 1209, CNRS UMR5309, 38000, Grenoble, France
- Plateforme BioPark of Archamps, 74160, Archamps, France
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2
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Diehn S, Zimmermann B, Tafintseva V, Seifert S, Bağcıoğlu M, Ohlson M, Weidner S, Fjellheim S, Kohler A, Kneipp J. Combining Chemical Information From Grass Pollen in Multimodal Characterization. FRONTIERS IN PLANT SCIENCE 2019; 10:1788. [PMID: 32082348 PMCID: PMC7005252 DOI: 10.3389/fpls.2019.01788] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 12/20/2019] [Indexed: 05/06/2023]
Abstract
The analysis of pollen chemical composition is important to many fields, including agriculture, plant physiology, ecology, allergology, and climate studies. Here, the potential of a combination of different spectroscopic and spectrometric methods regarding the characterization of small biochemical differences between pollen samples was evaluated using multivariate statistical approaches. Pollen samples, collected from three populations of the grass Poa alpina, were analyzed using Fourier-transform infrared (FTIR) spectroscopy, Raman spectroscopy, surface enhanced Raman scattering (SERS), and matrix assisted laser desorption/ionization mass spectrometry (MALDI-TOF MS). The variation in the sample set can be described in a hierarchical framework comprising three populations of the same grass species and four different growth conditions of the parent plants for each of the populations. Therefore, the data set can work here as a model system to evaluate the classification and characterization ability of the different spectroscopic and spectrometric methods. ANOVA Simultaneous Component Analysis (ASCA) was applied to achieve a separation of different sources of variance in the complex sample set. Since the chosen methods and sample preparations probe different parts and/or molecular constituents of the pollen grains, complementary information about the chemical composition of the pollen can be obtained. By using consensus principal component analysis (CPCA), data from the different methods are linked together. This enables an investigation of the underlying global information, since complementary chemical data are combined. The molecular information from four spectroscopies was combined with phenotypical information gathered from the parent plants, thereby helping to potentially link pollen chemistry to other biotic and abiotic parameters.
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Affiliation(s)
- Sabrina Diehn
- Department of Chemistry, Humboldt-Universität zu Berlin, Berlin, Germany
- BAM Federal Institute for Materials Research and Testing, Berlin, Germany
| | - Boris Zimmermann
- Faculty of Science and Technology, Norwegian University of Life Sciences, Ås, Norway
| | - Valeria Tafintseva
- Faculty of Science and Technology, Norwegian University of Life Sciences, Ås, Norway
| | - Stephan Seifert
- Department of Chemistry, Humboldt-Universität zu Berlin, Berlin, Germany
- BAM Federal Institute for Materials Research and Testing, Berlin, Germany
| | - Murat Bağcıoğlu
- Faculty of Science and Technology, Norwegian University of Life Sciences, Ås, Norway
| | - Mikael Ohlson
- Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, Ås, Norway
| | - Steffen Weidner
- BAM Federal Institute for Materials Research and Testing, Berlin, Germany
| | - Siri Fjellheim
- Faculty of Biosciences, Norwegian University of Life Sciences, Ås, Norway
| | - Achim Kohler
- Faculty of Science and Technology, Norwegian University of Life Sciences, Ås, Norway
- Nofima AS, Ås, Norway
| | - Janina Kneipp
- Department of Chemistry, Humboldt-Universität zu Berlin, Berlin, Germany
- BAM Federal Institute for Materials Research and Testing, Berlin, Germany
- *Correspondence: Janina Kneipp,
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3
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Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) shows adaptation of grass pollen composition. Sci Rep 2018; 8:16591. [PMID: 30409982 PMCID: PMC6224550 DOI: 10.1038/s41598-018-34800-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 10/22/2018] [Indexed: 11/22/2022] Open
Abstract
MALDI time-of-flight mass spectrometry (MALDI-TOF MS) has become a widely used tool for the classification of biological samples. The complex chemical composition of pollen grains leads to highly specific, fingerprint-like mass spectra, with respect to the pollen species. Beyond the species-specific composition, the variances in pollen chemistry can be hierarchically structured, including the level of different populations, of environmental conditions or different genotypes. We demonstrate here the sensitivity of MALDI-TOF MS regarding the adaption of the chemical composition of three Poaceae (grass) pollen for different populations of parent plants by analyzing the mass spectra with partial least squares discriminant analysis (PLS-DA) and principal component analysis (PCA). Thereby, variances in species, population and specific growth conditions of the plants were observed simultaneously. In particular, the chemical pattern revealed by the MALDI spectra enabled discrimination of the different populations of one species. Specifically, the role of environmental changes and their effect on the pollen chemistry of three different grass species is discussed. Analysis of the group formation within the respective populations showed a varying influence of plant genotype on the classification, depending on the species, and permits conclusions regarding the respective rigidity or plasticity towards environmental changes.
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4
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Lauer F, Diehn S, Seifert S, Kneipp J, Sauerland V, Barahona C, Weidner S. Multivariate Analysis of MALDI Imaging Mass Spectrometry Data of Mixtures of Single Pollen Grains. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2018; 29:2237-2247. [PMID: 30043358 DOI: 10.1007/s13361-018-2036-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Revised: 06/26/2018] [Accepted: 07/09/2018] [Indexed: 05/09/2023]
Abstract
Mixtures of pollen grains of three different species (Corylus avellana, Alnus cordata, and Pinus sylvestris) were investigated by matrix-assisted laser desorption/ionization time-of-flight imaging mass spectrometry (MALDI-TOF imaging MS). The amount of pollen grains was reduced stepwise from > 10 to single pollen grains. For sample pretreatment, we modified a previously applied approach, where any additional extraction steps were omitted. Our results show that characteristic pollen MALDI mass spectra can be obtained from a single pollen grain, which is the prerequisite for a reliable pollen classification in practical applications. MALDI imaging of laterally resolved pollen grains provides additional information by reducing the complexity of the MS spectra of mixtures, where frequently peak discrimination is observed. Combined with multivariate statistical analyses, such as principal component analysis (PCA), our approach offers the chance for a fast and reliable identification of individual pollen grains by mass spectrometry. Graphical Abstract ᅟ.
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Affiliation(s)
- Franziska Lauer
- Bundesanstalt für Materialforschung und-prüfung (BAM), Richard-Willstätter-Straße 11, 12489, Berlin, Germany
- Humboldt-Universität zu Berlin, Brook-Taylor-Straße 2, 12489, Berlin, Germany
| | - Sabrina Diehn
- Bundesanstalt für Materialforschung und-prüfung (BAM), Richard-Willstätter-Straße 11, 12489, Berlin, Germany
- Humboldt-Universität zu Berlin, Brook-Taylor-Straße 2, 12489, Berlin, Germany
| | - Stephan Seifert
- Bundesanstalt für Materialforschung und-prüfung (BAM), Richard-Willstätter-Straße 11, 12489, Berlin, Germany
- Humboldt-Universität zu Berlin, Brook-Taylor-Straße 2, 12489, Berlin, Germany
| | - Janina Kneipp
- Bundesanstalt für Materialforschung und-prüfung (BAM), Richard-Willstätter-Straße 11, 12489, Berlin, Germany
- Humboldt-Universität zu Berlin, Brook-Taylor-Straße 2, 12489, Berlin, Germany
| | - Volker Sauerland
- Bruker Daltonik GmbH, Fahrenheitstraße 4, 28359, Bremen, Germany
| | - Cesar Barahona
- Bruker Daltonik GmbH, Fahrenheitstraße 4, 28359, Bremen, Germany
| | - Steffen Weidner
- Bundesanstalt für Materialforschung und-prüfung (BAM), Richard-Willstätter-Straße 11, 12489, Berlin, Germany.
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Abstract
Proteomics encompasses a variety of approaches unraveling both the structural features, post-translational modifications, and abundance of proteins. As of today, proteomic studies have shed light on the primary structure of about 850 allergens, enabling the design of microarrays for improved molecular diagnosis. Proteomic methods including mass spectrometry allow as well to investigate protein-protein interactions, thus yielding precise information on critical epitopes on the surface of allergens. Mass spectrometry is now being applied to the unambiguous identification, characterization, and comprehensive quantification of allergens in a variety of matrices, as diverse as food samples and allergen immunotherapy drug products. As such, it represents a method of choice for quality testing of allergen immunotherapy products.
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Harvey DJ. Analysis of carbohydrates and glycoconjugates by matrix-assisted laser desorption/ionization mass spectrometry: An update for 2011-2012. MASS SPECTROMETRY REVIEWS 2017; 36:255-422. [PMID: 26270629 DOI: 10.1002/mas.21471] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Accepted: 01/15/2015] [Indexed: 06/04/2023]
Abstract
This review is the seventh update of the original article published in 1999 on the application of MALDI mass spectrometry to the analysis of carbohydrates and glycoconjugates and brings coverage of the literature to the end of 2012. General aspects such as theory of the MALDI process, matrices, derivatization, MALDI imaging, and fragmentation are covered in the first part of the review and applications to various structural types constitute the remainder. The main groups of compound are oligo- and poly-saccharides, glycoproteins, glycolipids, glycosides, and biopharmaceuticals. Much of this material is presented in tabular form. Also discussed are medical and industrial applications of the technique, studies of enzyme reactions, and applications to chemical synthesis. © 2015 Wiley Periodicals, Inc. Mass Spec Rev 36:255-422, 2017.
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Affiliation(s)
- David J Harvey
- Department of Biochemistry, Oxford Glycobiology Institute, University of Oxford, Oxford, OX1 3QU, UK
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7
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Simplifying the Preparation of Pollen Grains for MALDI-TOF MS Classification. Int J Mol Sci 2017; 18:ijms18030543. [PMID: 28273807 PMCID: PMC5372559 DOI: 10.3390/ijms18030543] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 02/24/2017] [Accepted: 02/27/2017] [Indexed: 12/16/2022] Open
Abstract
Matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS) is a well-implemented analytical technique for the investigation of complex biological samples. In MS, the sample preparation strategy is decisive for the success of the measurements. Here, sample preparation processes and target materials for the investigation of different pollen grains are compared. A reduced and optimized sample preparation process prior to MALDI-TOF measurement is presented using conductive carbon tape as target. The application of conductive tape yields in enhanced absolute signal intensities and mass spectral pattern information, which leads to a clear separation in subsequent pattern analysis. The results will be used to improve the taxonomic differentiation and identification, and might be useful for the development of a simple routine method to identify pollen based on mass spectrometry.
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8
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Xiao X, Miller LL, Parchert KJ, Hayes D, Hochrein JM. Atmospheric solids analysis probe mass spectrometry for the rapid identification of pollens and semi-quantification of flavonoid fingerprints. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2016; 30:1639-1646. [PMID: 27321852 DOI: 10.1002/rcm.7601] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 05/05/2016] [Accepted: 05/05/2016] [Indexed: 06/06/2023]
Abstract
RATIONALE From allergies to plant reproduction, pollens have important impacts on the health of human and plant populations, yet identification of pollen grains remains difficult and time-consuming. Low-volatility flavonoids generated from pollens cannot be easily characterized and quantified with current analytical techniques. METHODS Here we present the novel use of atmospheric solids analysis probe mass spectrometry (ASAP-MS) for the characterization of flavonoids in pollens. Flavonoid patterns were generated for pollens collected from different plant types (trees and bushes) in addition to bee pollens from distinct geographic regions. Standard flavonoids (kaempferol and rhamnazin) and those produced from pollens were compared and assessed with ASAP-MS using low-energy collision MS/MS. Results for a semi-quantitative method for assessing the amount of a flavonoid in pollens are also presented. RESULTS Flavonoid patterns for pollen samples were distinct with variability in the number and relative abundance of flavonoids in each sample. Pollens contained 2-5 flavonoids, and all but Kochia scoparia contained kaempferol or kaempferol isomers. We establish this method as a reliable and applicable technique for analyzing low-volatility compounds with minimal sample preparation. Standard curves were generated using 0.2-5 μg of kaempferol; from these experiments, it was estimated that there is approximately 2 mg of kaempferol present in 1 g of P. nigra italica pollen. CONCLUSIONS Pollens can be characterized with a simple flavonoid pattern rather than analyzing the whole product pattern or the products-temperature profiles. ASAP-MS is a rapid analytical technique that can be used to distinguish between plant pollens and between bee pollens originating from different regions. Copyright © 2016 John Wiley & Sons, Ltd.
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Affiliation(s)
- Xiaoyin Xiao
- Sandia National Laboratories, Albuquerque, NM, 87185, USA
| | - Lance L Miller
- Sandia National Laboratories, Albuquerque, NM, 87185, USA
| | | | - Dulce Hayes
- Sandia National Laboratories, Albuquerque, NM, 87185, USA
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9
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Seifert S, Weidner SM, Panne U, Kneipp J. Taxonomic relationships of pollens from matrix-assisted laser desorption/ionization time-of-flight mass spectrometry data using multivariate statistics. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2015; 29:1145-54. [PMID: 25981545 DOI: 10.1002/rcm.7207] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Revised: 04/01/2015] [Accepted: 04/01/2015] [Indexed: 05/09/2023]
Abstract
RATIONALE Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) has been suggested as a promising tool for the investigation of pollen, but the usefulness of this approach for classification and identification of pollen species has to be proven by an application to samples of varying taxonomic relations. METHOD MALDI-MS in combination with hierarchical cluster analysis (HCA) and principal component analysis (PCA) was used to delineate taxonomic relations between plants based on pollen biochemistry. To assess the robustness of the approach, pollen of 74 species of the plant orders Fagales and Coniferales were probed. RESULTS Discrimination at the levels of plant order and genus were achieved using the whole spectral range. In many cases, different species of the same genus could be distinguished. The sources of the spectral/chemical differences at the genus level can be understood using PCA. Specifically, typical mass regions for exact genus detection were identified. CONCLUSIONS Our results indicate that the chemical information represented by MALDI-TOFMS data is useful for reconstructing taxonomic relationships and is complementary to other chemical information on pollen from other spectroscopic data.
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Affiliation(s)
- Stephan Seifert
- Humboldt-Universität zu Berlin, Department of Chemistry, Brook-Taylor-Straße 2, 12489, Berlin, Germany
- BAM Federal Institute for Materials Research and Testing, Richard-Willstätter-Straße 11, 12489, Berlin, Germany
| | - Steffen M Weidner
- BAM Federal Institute for Materials Research and Testing, Richard-Willstätter-Straße 11, 12489, Berlin, Germany
| | - Ulrich Panne
- Humboldt-Universität zu Berlin, Department of Chemistry, Brook-Taylor-Straße 2, 12489, Berlin, Germany
- BAM Federal Institute for Materials Research and Testing, Richard-Willstätter-Straße 11, 12489, Berlin, Germany
| | - Janina Kneipp
- Humboldt-Universität zu Berlin, Department of Chemistry, Brook-Taylor-Straße 2, 12489, Berlin, Germany
- BAM Federal Institute for Materials Research and Testing, Richard-Willstätter-Straße 11, 12489, Berlin, Germany
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Touchard A, Dauvois M, Arguel MJ, Petitclerc F, Leblanc M, Dejean A, Orivel J, Nicholson GM, Escoubas P. Elucidation of the unexplored biodiversity of ant venom peptidomes via MALDI-TOF mass spectrometry and its application for chemotaxonomy. J Proteomics 2014; 105:217-31. [PMID: 24456813 DOI: 10.1016/j.jprot.2014.01.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Revised: 01/06/2014] [Accepted: 01/09/2014] [Indexed: 10/25/2022]
Abstract
UNLABELLED The rise of integrative taxonomy, a multi-criteria approach used in characterizing species, fosters the development of new tools facilitating species delimitation. Mass spectrometric (MS) analysis of venom peptides from venomous animals has previously been demonstrated to be a valid method for identifying species. Here we aimed to develop a rapid chemotaxonomic tool for identifying ants based on venom peptide mass fingerprinting. The study focused on the biodiversity of ponerine ants (Hymenoptera: Formicidae: Ponerinae) in French Guiana. Initial experiments optimized the use of automated matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) to determine variations in the mass profiles of ant venoms using several MALDI matrices and additives. Data were then analyzed via a hierarchical cluster analysis to classify the venoms of 17 ant species. In addition, phylogenetic relationships were assessed and were highly correlated with methods using DNA sequencing of the mitochondrial gene cytochrome c oxidase subunit 1. By combining a molecular genetics approach with this chemotaxonomic approach, we were able to improve the accuracy of the taxonomic findings to reveal cryptic ant species within species complexes. This chemotaxonomic tool can therefore contribute to more rapid species identification and more accurate taxonomies. BIOLOGICAL SIGNIFICANCE This is the first extensive study concerning the peptide analysis of the venom of both Pachycondyla and Odontomachus ants. We studied the venoms of 17 ant species from French Guiana that permitted us to fine-tune the venom analysis of ponerine ants via MALDI-TOF mass spectrometry. We explored the peptidomes of crude ant venom and demonstrated that venom peptides can be used in the identification of ant species. In addition, the application of this novel chemotaxonomic method combined with a parallel genetic approach using COI sequencing permitted us to reveal the presence of cryptic ants within both the Pachycondyla apicalis and Pachycondyla stigma species complexes. This adds a new dimension to the search for means of exploiting the enormous biodiversity of venomous ants as a source for novel therapeutic drugs or biopesticides. This article is part of a Special Issue entitled: Proteomics of non-model organisms.
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Affiliation(s)
- Axel Touchard
- CNRS, UMR Ecologie des Forêts de Guyane (EcoFoG), Campus Agronomique, BP 316, 97379 Kourou Cedex, France.
| | - Mélodie Dauvois
- VenomeTech, 473 Route des Dolines - Villa 3, Valbonne 06560, France
| | | | - Frédéric Petitclerc
- CNRS, UMR Ecologie des Forêts de Guyane (EcoFoG), Campus Agronomique, BP 316, 97379 Kourou Cedex, France
| | - Mathieu Leblanc
- VenomeTech, 473 Route des Dolines - Villa 3, Valbonne 06560, France
| | - Alain Dejean
- CNRS, UMR Ecologie des Forêts de Guyane (EcoFoG), Campus Agronomique, BP 316, 97379 Kourou Cedex, France; Université de Toulouse, UPS, INP, Laboratoire Écologie Fonctionnelle et Environnement (ECOLAB), 118 route de Narbonne, 31062 Toulouse, France
| | - Jérôme Orivel
- CNRS, UMR Ecologie des Forêts de Guyane (EcoFoG), Campus Agronomique, BP 316, 97379 Kourou Cedex, France
| | - Graham M Nicholson
- Neurotoxin Research Group, School of Medical & Molecular Biosciences, University of Technology, Sydney, NSW, Australia
| | - Pierre Escoubas
- VenomeTech, 473 Route des Dolines - Villa 3, Valbonne 06560, France
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11
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Weidner S, Schultze RD, Enthaler B. Matrix-assisted laser desorption/ionization imaging mass spectrometry of pollen grains and their mixtures. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2013; 27:896-903. [PMID: 23495059 DOI: 10.1002/rcm.6523] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2012] [Revised: 01/22/2013] [Accepted: 01/28/2013] [Indexed: 05/24/2023]
Abstract
RATIONALE The fast and univocal identification of different species in mixtures of pollen grains is still a challenge. Apart from microscopic evaluation and Raman spectroscopy, no other techniques are available. METHODS Matrix-assisted laser desorption/ionization (MALDI) imaging mass spectrometry was applied to the analysis of extracts of single pollen grains and pollen mixtures. Pollen grains were fixed, treated and covered with matrix directly on the MALDI target. RESULTS Clearly resolved MALDI ion intensity images could be obtained enabling the identification of single pollen grains in a mixture. CONCLUSIONS Our results demonstrate the potential and the suitability of MALDI imaging mass spectrometry as an additional method for the identification of pollen mixtures.
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Affiliation(s)
- Steffen Weidner
- BAM-Federal Institute for Materials Research and Testing, Richard Willstaetter-Strasse 11, D-12489, Berlin, Germany.
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